Hello everyone,
I constructed a Hanimandl a while ago based on version W.0.1 of Roland Rust’s code with a 2.4 inch display and a separate ESP32. It has worked very well and I have filled hundreds of jars of honey with it. Thank you Roland.
Even though it worked very well I wanted to make a nicer case and when I got a 3d printer I decided to design my own case.
About the same time I got a device called a 2432S028 (probably derived from 240 pixels x 320 pixels x 2.8 inches) which is an ESP32 and 2.8 inch display built into a neat PCB. Someone has decided to call it a Cheap Yellow Display (CYD). There are lots of resources available on line if you are interested. There are several versions available and I ordered one with an ST7789 display…. and received one with an ILI9341 display!
I did some experiments with it but it is very limited by its design considerations. There aren’t too many external GPIO pins available. It does have a touch screen, but it is resistive so not responsive with a finger, it needs a stylus to operate reliably.
I decided to try and get Hanimandl working on the CYD. It’s wasn’t easy! But not impossible.
The main problem is the lack of external GPIO pins. In the end I made some changes to the PCB by removing some of the surface mount components to release some of the GPIO pins and accessing the GPIO connections to the onboard microSD connector via a breakout board. I kept standard push buttons for the project.
The firmware side was surprisingly easy as Roland’s version uses the Arduino_GFX_Library for the display which also supports the CYD. It supports both the ST7789 and the ILI9341. I did need to reassign all the GPIO pins of course, and the CYD has an inbuilt amplifier for sound so the buzzer code was changed.
This time I used version W.0.2 of Roland’s firmware as it includes optional English language text. Again, thank you Roland. The code compiles with Arduino IDE to a simple ESP32 Wroom Dev Kit, not a CYD.
Please note this project is not trivial, you need a steady hand with soldering and removing very small SMD components and I used a microscope app on my phone to make the changes as everything is so tiny. If you damage your CYD then it’s your responsibility.
I’m happy to provide more details if there is enough interest.
The end result…. It works perfectly.


